Wednesday 17 November 2021

Grus grus!

Early to mid November is the peak migration time for Common Cranes Grus grus in Slovenia and in the wider Northern Adriatic region. In the last twenty or so years this migration event has become quite phenomenal, with every coming year hitting the records in terms of numbers. Thus, as reported by Dejan Bordjan (our national crane expert), in spring 2021 an estimated 93.000 Cranes migrated over Slovenia on the way to their North European breeding grounds. Now in autumn several thousands more already passed Slovenia on their southward migration to the Mediterranean, while many more have yet to do so in the next days. A first peak was had in a couple of days in late October, while the second wave is probably upon us right now. On Sunday 14th November a flock of around 1200 Cranes landed on the wet meadows of Cerkniško jezero, to rest and spend the night there during a spell of bad weather. Funny enough the next day I (Domen) had to count migrating Cranes over Postojna, but the weather didn't look promising - low clouds and fog shrouded the Javorniki mountains, where Cranes usually pass. So I decided to check Cerkniško jezero first thing in the morning. It was a great idea - hundreds of cranes were in the arable fields just north of the lake, putting on a great show. These rather shy animals require large open areas for landing, where human disturbance is at the lowest. It therefore took some time for all the noisy flocks to assemble in a quiet spot where they could forage in tranquility for some time. Still, dog walkers, tractors and the like probably made their stop quite stressfull. Eventually I succeeded in counting the gathered flocks and the tally stood at 750 birds - so only part of the large flock seen the day before.
Cranes Grus grus circling above arable fields near Cerknica (sound here).
Cranes resting in the field but still alert shortly after landing.
Many juveniles were within the flocks.
A Hortobagy-like scene.
Cranes assembled in the fields near Cerkniško jezero.
Cranes after they relaxed and began to feed intensively.
Short video of the Cranes - turn on the volume (also listen out for the juvenile's whistling calls).

While counting the Cranes I was also distracted by a few other good birds in the area. A quick look around the fields away from the Cranes produced an adult White-tailed Eagle Haliaeetus albicilla resting on a pole, 3 Hen Harriers Circus cyaneus, a Great Grey Shrike Lanius excubitor and a small flock of 8 White-fronted Geese Anser albifrons, the latter being a rather scarce species on the lake.
White-tailed Eagle Haliaeetus albicilla
White-fronted Geese Anser albifrons

Despite the weather conditions didn't improve much during the day, some flocks of Cranes apparently decided to migrate eventually. In the afternoon I observed 3 flocks of around 120-130 birds each, migrating above the Karst between Divača and Sežana (some over our house!) and heading straight towards the Adriatic (Trieste). A friend who saw them later near Trieste reported that the strong burja/bora wind swept them low, towards the sea, before they managed to take a small thermal and head west towards the lowlands of northeastern Italy.
Cranes Grus grus catching a thermal above our house!

A few days earlier, during fieldwork near Pivka, apart from several flocks of migrating White-fronted Geese Anser albifrons, we also observed a group of 6 Golden Plovers Pluvialis apricaria (a rare species in this area) being chased by a Peregrine Falco peregrinus. Also here were several Hen Harriers Circus cyaneus and a Great Grey Shrike Lanius excubitor - the two most typical winter birds of open farmland.

Golden Plovers Pluvialis apricaria near Pivka.
Hen Harrier Circus cyaneus - male.
Over the past weekend we did some local birding in the Karst around Divača. First we actually went to take some measurements in the habitat of Middle Spotted Woodpecker Leiopicus medius (which we heard several times). On the damp oak woodland floor we came across a nice Fire Salamander Salamandra salamandra, a typical amphibian of wet forest with small streams & frequently out in the wet November weather. Later on we moved to Škocjanske jame (Škocjan caves) where we spotted our first Wallcreeper Tichodroma muraria of the season. One to two Wallcreepers regularly winter at this site, while others choose the more thermophilous cliffs of the Karst edge. Even better than the terrible shot below is this video we made in phone-scoping (and yes, Domen is now on Twitter!).
Wallcreeper Tichodroma muraria
Mistle Thrush Turdus viscivorus
Fire Salamander Salamandra salamandra
A mighty Sessile Oak Quercus petraea in the habitat of Middle Spotted Woodpecker.

Monday 1 November 2021

Autumn colours in the Karst

Not much time for blogging lately and actually not much to report either. We are steadily advancing into the calmer (and most depressing) part of the year, when we need to be happy of the little things. Abundance of wildlife, diversity and colour seem already a distant memory. Mountain forests are falling silent as the last beech leaves are leaving the canopies. However the resident birds are still around. It is just more difficult to find them as they are mostly silent and roving in flocks. Recently we went tracking White-backed Woodpeckers Dendrocopos leucotos ssp. lilfordi on our usual circuits on mount Snežnik. Visiting a known territory, we located a fleeting female feeding at mid-height in the trees. The photos below show the typical feeding behaviour of the female, usually favouring rotten snags on live beeches, rather than feeding on the ground as males do more often. In our experience, following a female in the canopies is much more difficult than a male on the ground.

White-backed Woodpecker Dendrocopos leucotos ssp. lilfordi - before the peck...
...and after the peck.
White-backed Woodpecker Dendrocopos leucotos ssp. lilfordi (by Davide Scridel)
Beech snag in White-backed Woodpecker's habitat.

During our wanderings, we came (as usual) across a few Ural Owls Strix uralensis hunting along forest roads, including a quite dark, grey-morph individual (see photos). After the spring explosion, voles have literally disappeared from the forest floor and we guess the owls are now probably struggling to find food and are moving to other areas. This might explain the relative difficulty of seeing Ural Owls this autumn, when compared to spring. Nevertheless there were some other birds to keep us company like Black Woodpecker Dryocopus martius, Nutcracker Nucifraga caryocatactes, Brambling Fringilla montifringilla and the season's first Redwing Turdus iliacus. Among mammals we regularly saw Red Deer Cervus elaphus (including some shy stags with cool antlers) and even Chamois Rupicapra rupicapra in the subalpine forest on Snežnik's higher rocky outcrops. Signs of the presence of large carnivores aren't difficult to notice in these forests, as they are often found on forest roads. Thus we came across several fresh & old droppings of Wolf Canis lupus, as well as droppings & claw marks of Brown Bear Ursus arctos.
Ural Owl Strix uralensis - grey morph (note dark-barred facial mask).
Red Squirrel Sciurus vulgaris
Brown Bear's claw marks on a fallen trunk.
Bear's droppings containing some corn (from hunter's feeding stations).
Fresh (above) & old (below) scat of Wolf Canis lupus
Autumn in the Dinaric forests.
Wild places.
Beech Fagus sylvatica in its late-autumn phase.
Veliki Snežnik's summit dominating the forested plateau.
Morning mist over the Reka river valley.

Recently most of the time has been spent locally in the Karst around Sežana. Late October and early November is the best time to enjoy the amazing autumn colours of the karstic shrubs and meadows, where the typical Smoke Bush Cotinus coggygria steals the show. However the cold and unpleasant burja wind persisted for most of October and made birding in the Karst's woodlands and meadows quite impossible. Nevertheless we were very glad when we found a Middle Spotted Woodpecker Leiopicus medius on a hill close to home, as well as other goodies such as Black Woodpecker Dryocopus martius, Brambling Fringilla montifringilla and the first Common Cranes Grus grus of the season, migrating south-west (heard only on Oct 18).

Montpellier Maple Acer monspessulanus - a typical tree of the karstic shrub.
Smoke Bush Cotinus coggygria - the autumn essence of the Karst.
Limestone scree on the top of a karstic hill, covered in Smoke Bush.
Karstic oak woodland - home of a recent coloniser, the Middle Spotted Woodpecker.
Autumn colours in the oak woodlands.
Views E and SE from Stari tabor (603 m), a panoramic hill between Sežana and Lokev.
Stari tabor (603 m) with mount Nanos in the distance.
Smoke Bush stealing the show... and Sara stealing the Smoke Bush!